Art of separating metals from matte.



To cll'who'm it may concern:

Be it known that we, ALBION J. WAnnAMs,

taining nickel, coba t,

' other metals of the speiss.

UNITED STATES PATENT oEFIoE.

ALBIO N J. WADHAMS, 0F R IvERroN, NEW-JERSEY, AND ROBERTO. STANLEY, OF NEW BRIGHTON, NEW YORK, ASSIGNORS TO INTERNATIONAL NICKEL, oOMPA Y, OF BAYONNE, NEW JE SEY, A CORPORATIONOF NEW JERSEY. A I

. ART OF sErA A'rIN'e METALS FRQM MATTE.

Specification of Letters Patent.

Patented Oct. e, 1908.

Application filed February 16, 1907. Serial No. 857,718.

of Rivertofi, county of Burlington, and State of New Jersey, and ROBERT C. STANLEY, of New Brighton, county of Richmond, and State ofNew York, have invented an Imrovement in the Art of Separating Metals om Matte, of which the following is a specification.

The purpose of our invention is to provide a cheap and effective means for the separation of cop er, nickel, cobalt and silver from arsenic an other elements with which they are associated in. sp'eiss or other arsenical matte, and to se arate the silver from the copper, nickel, co alt and iron. The processes heretofore employed for this purpose have been diflicult and to a large extent wasteful, but our process reduces the cost to a very small amount and provides means by. which the values are recovered with little or no waste.

Our invention is ap licable to matte consilver and iron, whether copper is contained therein or not. We first eliminate the arsenic from the This we accomplish preferably by roasting the speiss or concentrate in a calcining furnace at a cherry red heat until arsenical fumes cease to be liberated therefrom. We then take the calcined material, grind it with carbon preferably in the form of coal or charcoal, and roast the mixture in a reducing atmosphere, which reduces the arsenical compounds into arsenids, and we then subject the mixture to an oxidizing roast which liberates arsenic fumes. The alternatereductionand oxidation are repeated in this manner until fumes of-arsenic cease to be liberated. If this operation is carried to the limit, material which originally nickel, 25 per cent. cobalt, and 10 per cent. 1

contained 35 per cent. arsenic, 16 per cent.

iron,will contain about 4 per'centrof arsenic. To eliminate this residue we preferably proceed as follows :-We mix the material with nitrate of soda and soda ash which are employed preferably in the proportion of 1 part of nitrate of soda and two parts of soda ash to one part of arsenic contained in the comound, and we then calcine the mixture in a mace, preferably at a cherry red heat, until all of the arsenic is converted into arsenate of soda. We then withdraw the material from 'per cent.

the furnace and wash it, preferably in a washtank, although we may employ mechanical stirrers or a filtering apparatus, until the arsenate of soda has been dissolved. We

then prefer to/ concentrate the solution by i evaporation and remove the arsenate of soda by crystallization, as it is a valuable product.

The undissolved material is separated and dried with heated air, and by the treatment above described the ercentage of arsenic can be brought to as ow as one-half'of one The residual material consists of oxids of copper, nickel, cobalt and iron, together with other oxids .such as silicon, aluminum and calcium, and metallic silver, but it is substantially free from arsenic or arsenate of soda. solved in hydrochloric acid, which is preferably concentrated, and in order to obtain the most rapid and effective solution we prefer to perform it in arevolving cylinder under pressure and with the influence of heat. We

ave obtained suitable results with an internal pressure in the'cylinder of about to 80 ounds, the acid being heated to about 135 .and the treatment continued from six to eight hours. The hydrochloric acid dissolves the chlorids of the several metals pose we prefer to mix the solution with an alkali, preferably caustic lime, which precipitates the iron as a hydrate and also re-- moves. the last of the arsenic, but holds the silver in solution. The solution, freed from iron and still acid, is treated for the removal of copper and silver by assing sulfureted hydrogen through it, whio precipitates the copper and silver as sulfids; or the solution.

may be passed over cop or or zinc, on which the silver will deposit y cementing. The precipitate of silver and copper su fids, or cemented silver, may be washed and collected and smelted in a furnace. After this treatment the solution contains chlorids of nickel and cobalt, and can be treated by known methods for the separation of these metals as oxids.

Within the scope of our invention as de- The material is then dis- 2 arsenic from speiss containingcobalt, nicke silver and iron, treating the residue with rating metals, which consists in removing 'fined in the" broader claims, the steps of the operation may be modified in various ways, and the several steps may be used in other combinations. For example, the prelimi- .5 nary step by which the arsenic is removed from the speiss may be substituted by other means for the separation of the arsenic, since What we claim is: 1. The method herein described of sepa- 10 rating silver from cobalt, nickel and iron, I whic consists in treating the material with hydrochloric acid, thereby dissolving nickel, cobalt and iron, leaving silver mainly undissolved as chlorid or metallic silver,.adding 5 an alkali to precipitate iron and to hold the dissolved portion of the silver in solution, and then separatin the silver.

2. The method erein described of separating metals, which consists in removm arsenic from speiss containing cobalt, nickel, silver and iron, by alternately subjecting the speiss to oxidizing and reducing roast, then completing the removal of arsenic by roasting the material with a sodium compound and converting the arsenic into arsenate of soda, dissolving the arsenate of soda therefrom, and then treating the residue with hydrochloric acid and se arating silver from the solution; substantial as described.

4. The method herein described of separating metals, which consists in removin arsemc from speiss containing cobalt, nickel? silver and iron, treating the residue with hydrochloric acid, precipitating iron from the solution by treatment with an alkali, and.

then separating silver therefrom; substantially as described.

In testimony whereof, we have hereunto set our hands.

ALBION J. WADHAMS. ROBT. O. STANLEY.

Witnesses:

GEORGE H. .SONNEBORN, ANNA E. WALLACE. 

